Defective insulations of electrical conductors are a source of danger in multiple respects. Stresses of the insulation materials, for example as a result of high electric fields or mechanical stress, can lead to insulation changes or insulation rupture. The bare conductor sections can cause a short circuit as a result of body contact. The short-circuit current can lead to damage as a result of overheating in the course of lines and cables, but also in electrical switchgear installations. Therefore, insulation monitoring is important particularly in the case of current conduction elements that carry high powers.
Insulation monitoring is a prerequisite for safe handling of current conduction elements. This becomes ail the more important if the current conduction element not only is intended for handling but also carries a high power.
By way of example, charging cables for charging energy storage units of electric or hybrid vehicles have high voltages. The charging cable is situated either at the charging station or directly at the vehicle and connects the charging station to the vehicle during the charging process. Operation here is usually effected by the user of the charging station himself/herself. It is desirable to ensure that the charging cables have an intact insulation in order to preclude endangerment of the users when operating the charging cable.